A bitcoin conference in Miami has stopped accepting bitcoin from customers wanting to buy last-minute tickets with cryptocurrency and has placed the blame on high fees and network "congestion".

The North American Bitcoin Conference – self-described as the "most important blockchain conference of the year" – confirmed on its booking page that bitcoin can no longer be accepted.

"Due to network congestion and manual processing, we have closed ticket payments using cryptocurrencies," a brief statement read.

It continued: "Hopefully, next year there will be more unity in the community about scaling and global adoption becomes reality.

"We have, and always will, accept cryptocurrencies for our conferences up to 14 days before the event.

"However, due to the manual inputting of data in our ticketing platforms when paid in cryptocurrencies we decided to shut down bitcoin payments for last-minute sales due to print deadlines."

The two-day conference, part of the World Blockchain Forum, is scheduled to kick off on 18 January.

One organiser, Moe Levin, told Bitcoin.com: "Ticket service providers like Eventbrite or others do not have [cryptocurrency] integrations yet. I think within a year companies like Coinpayments and other payment providers will have better tools and we will instantly integrate.

"We wish this was easier but no ticketing options exist which can handle large volumes of ticket sales and transaction fees on the bitcoin blockchain exceed $30 at certain times of the day."

The announcement came after billionaire investor Warren Buffet said in an interview with CNBC that he believed with "almost certainty" that cryptocurrencies would come to a bad ending. He did, however, acknowledge that his fintech knowledge was lacking.

"We don't own any, we'll not short any, we'll never have a position in them," he said.

"I get into enough trouble with things I think I know something about," he added. "Why in the world should I take a long or short position in something I don't know anything about."

Internet money

Bitcoin and its many competitors are essentially forms of internet money. They do not need banks to operate and are typically based on distributed ledger tech known as a blockchain.